I'm not and never have been pregnant, but i'll give you a bit of advice for after the baby is born. Let your son be involved in the care of his little brother/sister. He doesn't have to do much, just let him know that they're both part of the family. Makes the kid feel important, and it probably encourages bonding. Good luck!
Hey, where in england are you? I'm in west yorkshire.
Diamond, I can beat that. :p xander and lex, my youngest brother and sister, are 13 months apart. Hard work, but they're like twins now.